This invention relates generally to packaging arrangements for large, heavy, manufactured goods and particularly relates to packaging arrangements in the form of shipping frames for such goods, the shipping frames being made of structural foam plastic materials that can be re-used and can be covered by a corrugated outer carton.
Previously, corrugated board has been used to package large and heavy manufactured goods such as marine outboard engines and other small gasoline engines such as are used on lawn mowers. For goods such as an outboard engine, sheets of single and multiple thickness corrugated paperboard are cut and folded into many different detail parts. The detail parts are held to one another by gluing and stapling and are fitted to the engine powerhead, stern mounting bracket and lower gear case. The assembled engine and packaging detail parts then are slipped into a sleeve-like plural thickness corrugated board shipping carton that is afterwards sealed at both ends. The sealed cartons can then be placed in a warehouse for storage or can be shipped to a dealer for retail sale.
This form of packaging has exhibited some inadequacies. The cost of forming the detail parts has increased greatly. Large sheets of corrugated board need to be accurately cut, folded and fastened by gluing or stapling to result in the many detail parts and a large or tall finished carton. This requires skill, factory floor space and much hand labor. Next, the goods have to be hand packed with the correct detail parts inserted at the proper locations to insure adequate cushioning and to protect any decorative surfaces and covers. A shortage of one detail part stops the packaging of all the goods, requiring costly investment in sufficient inventory of all such detail parts.
Often the detail parts are improperly assembled to the goods, resulting in the goods falling loose when inside the carton. This requires the carton to be opened, the damaged goods to be repaired or replaced, and the carton to be repacked. The sealed cartons occasionally are carried in the factory to the warehouse or to shipping trucks by side-lift fork trucks. The lift truck squeezes two side-by-side sealed cartons together to lift and move them. Heavy goods such as marine engines require a great squeezing force on the cartons to effect the lifting. Such squeezing force often crushes the internal detail parts, resulting in the cartons slipping from the lift truck and damaging the enclosed goods.
Additionally, the detail parts and shipping carton are often arranged to hold or suspend the enclosed goods vertically to reduce the center of gravity of the carton. This prevents shipping the packed cartons on their sides because of the weakness of the carton in that direction. This limits the number of cartons that can be placed side-by-side in a truck. Further, the large quantity of corrugated packaging materials can add substantial weight to the shipping weight of the goods.
In a warehouse, the corrugated cardboard cartons can absorb moisture that significantly lowers their strength. This has resulted in the lower carton of a stack buckling under the weight of the upper cartons and causing the stack to fall, often damaging the contained goods, and always requiring weakened cartons and internal detail parts to be replaced. This problem of corrugated board weakening due to moisture absorption is pronounced at seaports, where it has been known for side-lift trucks to rip the outer carton off the enclosed goods because the carton and detail parts had greatly weakened due to the high ambient moisture.
A lawn mower manufacturer can have substantial problems with unpacking. Gasoline engines are shipped from their manufacturer to the lawn mower assembly plant in corrugated cartons, often several engines per carton. These mower engines are much lighter than finished marine outboard engines, but still are of significant weight and must be protected from shipping damage by many detail parts that have been hand fabricated and inserted around the engines in the cartons. Unpacking daily shipments of numerous mower engines can require several full-time employees and produces a large quantity of scrap corrugated board refuse. Recycling the scrap corrugated board is possible, but only if it is free of metal banding material often used to close the shipping cartons.
One way to reduce or eliminate the number of detail parts made from corrugated board is by molding styrofoam or urethane foam shells. In other packaging situations, the shells are formed to receive the manufactured goods, such as electronic audio and video equipment, nested in specially shaped cavities between the top and bottom halves. Styrofoam, however, has insufficient strength to carry a heavy outboard marine or lawn mower engine, and urethane foam is too rigid to cushion and absorb the shock that such an engine experiences in shipment.
While many of the problems in packaging and unpacking large, heavy finished manufactured goods are exemplified by the problems associated with marine outboard engines and lawn mower engines, the present invention is believed to apply to many other packing situations faced with like or similar problems.
Inboard marine engines present additional problems due to their heavy weight which typically is 500 to 700 pounds, in packaging for shipping and storing. Previously, the marine engine, which substantially is a four, six or eight cylinder internal combustion engine, is bolted to a skid that has been fabricated from wooden components. A heavy corrugated, doublethickness box then is placed over the engine after wooden vertical supports are fixed therein.
The packaged inboard engines then have been stacked four high in a warehouse and have been shipped two high in a truck for delivery to the distributor and customer. The packaging arragements for these inboard engines present substantially all of the previously described problems including the multiple packaging parts that need to be stocked and assembled and the possible weakness of the packaging materials to support like packages in a multiple package stack. The wooden supports used in all of the described packages vary in strength from board to board making consistently strong packages difficult to attain.
Shipping packages, formed of plastic materials, have been known. For example U.S. Pat. No. 4,284,990 to Kurick discloses a pair of polystyrene shells that engage several automotive glass windshielded therebetween. The curved glass sheets are rigidly bound against a pair of rigid support members extending up from a bottom wall while webbed bottom and top walls and solid peripheral side walls protect the glass sheets from intrusions and damage.
One drawback is that this arrangement of the packaging transmits the weight of the glass directly through the solid support members to the bottom wall requiring the material of the suport members alone to absorb all shock and other forces. Another drawback is that such an arrangement of webbed bottom and top walls and solid peripheral side walls for an inboard or outboard engine would weigh more than the present corrugated board and wood packaging. Some other more resilient and light weight design is desired.
U.S. Pat. No. 4,366,905 to Forshee also discloses a material handling rack, made of Zytel nylon, that can receive and carry small or large parts or units and that is capable of being loaded into transportation vehicles by conventional fork lift trucks. The rack of Forshee comprises four corner posts, two lower side rails and two lower end rails, made of plastic, that are fastened together into a structure forming a bottom rectangle with upstanding posts at the corners. The open areas between the corner posts and rails can be closed with panel members to form an open box. Molded transverse rails can be fastened between the side rails to support machine components such as auto transmissions, but these transverse rails include depending webs to transmit the carried weight downwardly to an underlying floor and not to the side or end rails. This design presents the drawbacks of requiring manual assembly and inventory of the necessary parts and fasteners to assemble same and uses the side and end rails as guards against intrusion and not as primary weight carrying and shock absorbing members.
U.S. Pat. No. 4,491,076 to Forshee discloses a structure having four vertical walls that transmits the weight of the carried components, such as auto transmissions, through the vertical walls to the corner posts, but comprises many molded Zytel nylon parts that must be seprately molded and assembled for use.
A shipping package for large or heavy components that overcomes these undesireable aspects is desired.